Field, Mineralogical And Petrographic Features Of The Miocene Lava Around Sağlık And Yatağan Area, Western Konya/Türkiye

Abstract

Extensive lava domes occur west of Konya as a component of subduction-related Neogene Erenlerdağı volcanism. These light grey to grey-coloured domes commonly give rise to topographic elevations and contain some Mafic Microcrystalline Enclaves (MME) with a well-developed chilled zone, up to 4 mm thick. Petrographical and modal image analysis show that the lava samples consist predominantly of plagioclase (andesine, 8-46%, 0.11-4.3 mm), amphibole (3-17%, 0.14-1.613 mm), clinopyroxene (0-14%, 0.035-1.845 mm), biotite (3-12%, 0.09-2.30 mm), epidote (0-8%, 0.078-0.166 mm), piemontite (0-3%, 0.145-0.562 mm), quartz (0-6%, 0.4-2.0 mm), sanidine (0-5%, 0.10-0.17 mm), and opaque iron ore (3-43%), along with accessory minerals apatite and zircon, in various textures, including holocrystalline porphyritic, hypocrystalline porphyritic, glomeroporphyritic, and synneusis. The chilled zone is characterised by phenocrysts of plagioclase (25%) and amphibole (5%) in a holocrystalline porphyritic texture. The amphibole shows opacification and calcitization. The matrix includes plagioclase, amphibole (0.3-0.4 mm), epidote, opaque minerals and rare volcanic glass. The petrographical study suggests that the lava likely experienced mixing or mingling processes during the replenishment of felsic magma by mafic magma, potentially triggering a volcanic eruption. The crystallisation of skeletal and acicular microphenocrysts of plagioclase and acicular apatite indicates rapid crystallisation under undercooled conditions. © 2024, Gumushane University. All rights reserved.